The SQL COUNT function returns the number of rows in a query. NULL value will not be counted.
SQL SELECT DISTINCT
The SQL SELECT DISTINCT statement is used to select distinct(different, unique) value of centain database table column(s), and remove the duplicates from the result. The usage of this statement is same among MS SQL Server, Oracle, MySQL.
SQL SELECT INTO
The SQL SELECT INTO statement has different implementations from one product to another. This topic will talk about its implementations in MS SQL Server, Oracle and MySql.
SQL Select Top
Table: Employees
| EmployeeId | FirstName | LastName | Department | Salary |
|---|---|---|---|---|
| 203 | Mary | Fox | Finance | 78000 |
| 204 | Joe | Lanyon | Finance | 45800 |
| 205 | Sally | Daff | Finance | 57000 |
| 206 | Grace | Salter | Finance | 62000 |
| 302 | James | Band | Development | 75000 |
| 303 | Dona | Earl | Development | 55000 |
| 304 | Tony | Oakes | Development | 49000 |
| … | ||||
SQL SELECT Statement
The SQL SELECT statement is used to select data from SQL database.
It returns a result-set which stores the result as a table.